Struct salty::CompressedY

pub struct CompressedY(pub [u8; 32]);

“Compressed” form of a EdwardsPoint, whereby the sign of the x-coordinate is stuffed in a spare bit of the y-coordinate

Implementations

impl CompressedY

pub fn decompressed(&self) -> Result<EdwardsPoint>

This is rather tricky: to get the x-coordinate, and not just its sign, need to calculate the square root of u/v := (y**2 - 1)/(dy**2 + 1). Moreover, we want to detect whether our compressed Y actually corresponds to a point on the curve! The original sources are the Tweet NaCl paper, section 5 and the ed25519 paper, also section 5.

impl CompressedY

pub fn as_bytes(&self) -> &[u8; 32]

pub fn to_bytes(&self) -> [u8; 32]

Trait Implementations

impl Clone for CompressedY

fn clone(&self) -> CompressedY

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ConstantTimeEq for CompressedY

fn ct_eq(&self, other: &Self) -> Choice

Determine if two items are equal.

impl Debug for CompressedY

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for CompressedY

fn default() -> CompressedY

Returns the “default value” for a type.

impl From<&'_ [u8; 32]> for CompressedY

fn from(bytes: &[u8; 32]) -> CompressedY

Performs the conversion.

impl PartialEq<CompressedY> for CompressedY

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Copy for CompressedY